Most common presenting symptom of threadworm infection amongst the following is -

Most patients infected of thread worm/pin worm/seat worm /Enterobius vermicularis are asymptomatic. Most common complaint: Perianal and perineal pruritus (pruritus ani)- nocturnal/early morning. Other complaints: Abdominal pain, irritability and restlessness. All these symptoms caused by the female worms laying eggs on anal area. Severe infections: Sleep disturbances, neurosis, nail bite, grinding teeth at night. Adult worms can cause appendicitis.